Performance of Nitrogen-doped Hollow Carbon Spheres as Oxidase Mimic

Abstract

Due to efficient performance and stability, nanozymes have recently attracted much attention in bioreaction.In this work, a facile approach for preparing N-doped hollow carbon sheres (N-HCSs) by using CaCO 3 spheres as green template and polydoamine as nitrogen and carbon sources was reported. Morphologies and structures of the samples were characterized. Using TMB (3,3,5,5 tetramethylbenzidine) as a substrate, UV spectra photometry was used to investigate its oxidase-like activity and catalytic mechanism. The results showed that N-HCSs displayed oxidase-like activity. The oxidase-like activity of N-HCSs increased by three times after activation by KOH. These enzymes conform to the Michaelis-Menten kinetic equation, and the K m constant before and after activation were 0.105 and 0.083, respectively, indicating good affinity for substrates. The data demonstrate that it is superoxide anion